OrbitalHub

ULA dixit:

“CisLunar – the space between Earth and the moon – holds vast opportunities for humans. Reliable, accessible, affordable access to space will help open economic opportunities. ULA’s ability to provide reliable, affordable access to space, which will provide critical infrastructure to supporting a space economy.”

Wikipedia dixit:

“Originally proposed as the Advanced Cryogenic Evolved Stage by Boeing in 2006 as a concept for use as a new Delta IV second stage — and subsequently, the Advanced Common Evolved Stage by its corporate successor, United Launch Alliance by 2010 — ACES was intended to boost satellite payloads to geosynchronous orbit or, in the case of an interplanetary space probe, to or near to escape velocity. Other alternative uses included a proposal to provide in-space propellant depots in LEO or at L2 that could be used as way-stations for other rockets to stop and refuel on the way to beyond-LEO or interplanetary missions, and to provide the high-energy technical capacity for the cleanup of space debris.

The late-2000s ACES proposal by ULA also had a predecessor at Lockheed Martin, prior to the merger of Boeing and Lockheed Martin launch vehicle manufacturing and operations to form ULA in 2006. Known then as the Lockheed Martin common-stage concept, the upper stage was intended to “provide efficient, robust in-space transportation”, and take advantage of the high-mass fraction that is enabled by Centaur’s design and its common bulkhead to minimize combined LO2/LH2 boil off. A study funded by NASA led to the development of the Lockheed Martin concept known as ACES, under the original name of Advanced Cryogenic Evolved Stage as of 2006.

In April 2015, after ULA had announced the end of production of the Delta IV Medium in 2019 and the Delta IV Heavy in the mid-2020s, ULA renamed the stage the Advanced Cryogenic Evolved Stage, as ACES would in this case serve as the second stage on only a single launch vehicle, the Vulcan, beginning no earlier than 2023.

After the formation of ULA in 2006, the ACES concept became one that would provide a common stage that would be evolved from both Atlas and Delta rocket technology and could be used on both launch vehicles — thus “common”. The concept by 2010 was to utilize the new high-performance upper stage, if built, on both Atlas V and Delta IV/Delta IV Heavy launch vehicles. As further refined in a 2010 conference paper, ACES was intended to be a lower-cost, more-capable and more-flexible upper stage that would supplement, and perhaps replace, the existing ULA Centaur and Delta Cryogenic Second Stage (DCSS) upper stage vehicles.

In April 2015, ULA renamed the stage the Advanced Cryogenic Evolved Stage, and announced conceptual plans to complete development of the ACES technology for the Vulcan launch vehicle, flying no earlier than 2023, but currently planned for 2024-25. No plans to develop the stage for the Atlas V or Delta IV launch vehicle lines remain. However, just like earlier ACES concept proposals, ACES would continue to blend technical aspects of both Delta and Atlas technologies and manufacturing processes, as well as use ULA’s proprietary Integrated Vehicle Fluids (IVF) technology to significantly extend the ability of the upper stage to operate in space long term. The IVF technology utilizes a lightweight internal combustion engine to use propellant boiloff (normally wasted when boiloff gasses are vented to space) to operate the stage including production of power, maintaining stage attitude, and keeping the propellant tanks autogenously pressurized, eliminating the need for hydrazine fuel and liquid helium.

The ACES vehicle is “based on a simple modular design” where the “use of multiple barrel panels, similar to Centaur, provides a straightforward means to building multiple-length (propellant load) stages that are otherwise common. The common equipment shelf accommodates one, two, or four RL10 engines. While ACES can start with existing Centaur and Delta pneumatic, avionics and propulsion systems it is intended to transition to lower-cost and higher capability systems founded on the Integrated Vehicle Fluids (IVF) system concept. IVF eliminates all hydrazine, helium, and nearly all batteries from the vehicle. It consumes waste hydrogen and oxygen to produce power, generate settling and attitude control thrust, and autogenously pressurize the vehicle tanks. IVF is optimal for depot operations since only LH2 and LO2 need be transferred, and it extends mission lifetimes from the present dozen hours to multiple days.” With the addition of a solar power system, the vehicle can remain in space and operate indefinitely.”

Video credit: ULA

Credits: ISRO

After nine months of operation, Chandrayaan-1 failed to communicate with the base. The Indian Space Research Organization (ISRO) abruptly lost contact with the spacecraft on Saturday, September 29, 2009.

If this is the end of Chandrayaan-1, the mission covered only nine months of its scheduled two-year operational life. I really hope that this is a minor obstacle that the ISRO will be able to overcome. ISRO stated that the Chandrayaan-1 mission was able to meet most of its scientific objectives.

The Chandrayaan-1 scientific payload contains a diverse collection of instruments. The instruments were designed and developed by ISRO, ESA, NASA, and the Bulgarian Space Agency.

There are two instruments that are used to map the surface of the Moon: the Terrain Mapping Camera (TMC) and the Lunar Laser Ranging Instrument (LLRI). The X-ray spectrometer onboard the spacecraft measures the concentration of certain elements on the lunar surface and monitors the solar flux in order to normalize the results of the measurements taken. The mineralogical configuration of the surface is mapped by four instruments: the Hyper Spectral Imager (HySI), the Sub-keV Atom Reflecting Analyzer (SARA), the Moon Mineralogy Mapper (M3), and the Near-Infrared Spectrometer (SIR-2). The Radiation Dose Monitor (RADOM-7) records the radiation levels in the lunar orbit.

You can find out more about Chandrayaan-1 on the ISRO’s dedicated web page.

Credits: NASA

The Gravity Recovery And Interior Laboratory (GRAIL) is a mission that will measure the lunar gravity field in unprecedented detail. The twin spacecraft will orbit the Moon in tandem and collect scientific data for several months.

The GRAIL mission will cost $375 million and launch in 2011 as part of NASA’s Discovery Program. The window for the launch is 26 days long and opens on September 8, 2011.

After a dual launch aboard a Delta II 2920-10, the spacecraft will spend three to four months cruising on a low-energy trans-lunar trajectory. The two spacecraft will orbit the moon on 50 km, near-circular polar orbits, with a spacecraft separation of 175 – 225 km. The science phase of the mission will take 90 days, and it will be followed by a 12-month science data analysis.

The technique used by GRAIL for collecting scientific data was also used for the Gravity Recovery And Climate Experiment (GRACE) mission, launched in 2002. Small changes in the distance that separates the two spacecraft are translated in variations of the lunar gravity field.

The GRAIL spacecraft are based on the Lockheed Martin XSS-11 bus. The XSS-11 (Experimental Small Satellite 11) is the result of research done at Lockheed Martin Space Systems in the field of agile and affordable micro-satellites. Interesting to mention here is that there were speculations that XSS-11 could also be used as the base for the development of a kinetic anti-satellite weapon (ASAT).

The spacecraft is a rectangular composite structure. Two non-articulated solar arrays and lithium ion battery provides power. The attitude control system, the power management system, and the telecommunications system are also inherited from the XSS-11 bus.

The payload consists of a Ka-band Lunar Gravity Ranging System (LGRS), which is derived from the instrument carried by the GRACE spacecraft.

The spacecraft flight operations will be conducted from Lockheed Martin’s Denver facility. Science Level 0 and 1 data processing will be done at Jet Propulsion Laboratory (JPL), Level 2 data processing at JPL, the Goddard Space Flight Center (GSFC) and the Massachusetts Institute of Technology (MIT). The final scientific data will be delivered by MIT.

While missions like the Lunar Reconnaissance Orbiter (LRO) will find safe landing sites, locate potential resources, and take measurements of the radiation environment of the lunar surface, GRAIL will explore the moon from crust to core, and determine the moon’s internal structure and evolution.

More information about GRAIL is available on the GRAIL mission page on MIT’s web site.

Courtesy of JAXA/NHK

On September 14th, 2007, the Japan Aerospace Exploration Agency (JAXA) launched the second Japanese lunar explorer, Kaguya. Kaguya was launched by an H-IIA Launch Vehicle from the Tanegashima Space Center (Mitsubishi Heavy Industries, Ltd. has a special page dedicated to the H-IIA No. 13, which was the rocket used for the Kaguya mission).

Kaguya shared the journey to the Moon with two smaller satellites, Okina and Okuna. Once in lunar orbit, Kaguya released the small satellites on elliptical orbits around the Moon. Okina and Okuna play the role of orbiting radio transmitters, relaying the data from Kaguya back to Earth in real time when Kaguya is above the far side of the Moon.

Courtesy of JAXA/NHK

The instruments onboard the spacecraft have measured the composition and the topography of the lunar surface for more than one year.

Mapping of the lunar magnetic field was also performed.

The NHK HDTV cameras on Kaguya recorded stunning movies of the Earth rising and setting over the lunar surface. The movies are now available on JAXA’s web site.

Credits: NASA

In the previous two posts in this series, we presented NASA’s Lunar Reconnaissance Orbiter (LRO) and the Chandrayaan-1 mission, which was designed and developed by ISRO. These two missions are typical lunar scouting missions: the spacecraft with onboard remote-sensing instruments will orbit the Moon, collect scientific data, and relay it back to Earth.

NASA will launch another lunar scouting spacecraft on the same Atlas V rocket with LRO: the Lunar Crater Observation and Sensing Satellite (LCROSS). This mission is not a typical scouting mission and we will see why in this post.

In 1999, a precursor of LRO and LCROSS called the Lunar Prospector detected traces of concentrated hydrogen at the lunar poles. As a result, the LCROSS mission’s main goal is to confirm the presence or absence of water in a permanently shadowed crater near a lunar polar region. At the present time, landing a probe on the lunar surface and performing excavations or drilling would be very expensive. A less expensive solution for the LCROSS mission is to use a kinetic impactor to excavate a crater on the surface of the Moon.

Credits: NASA

After the launch, LRO will separate from LCROSS, and continue on a solo journey to the Moon. LCROSS will remain attached to the Centaur upper stage of the Atlas V launch system.

While LRO will follow a trajectory that will place it in a polar lunar orbit, LCROSS will execute a flyby of the Moon, and use an elongated Earth orbit to position itself on an impact trajectory. During this time, the LCROSS mission team will perform instrument calibration and corrections for the impact trajectory. The target of the impact will be the lunar south pole.

Seven minutes before the impact, LCROSS will separate from Centaur. The Centaur will be used as a kinetic impactor. Having a mass of approximately 2,200 kg, on impact, it will excavate a crater 20 meters wide and 3 meters deep. According to NASA scientists, more than 250 tons of lunar material will be propelled into space.

Credits: NASA

LCROSS will then fly through the debris of the previous impact. The instruments onboard LCROSS will collect scientific data and the spacecraft will relay it back to Earth. LCROSS will end its mission four minutes after the Centaur impact by creating its own impact crater on the lunar surface. The last S in LCROSS should stand for Smasher instead of Satellite considering the final act of the mission!

The scientific instruments onboard LCROSS cover a wide spectrum: two near-infrared spectrometers, a visible light spectrometer, two mid-infrared cameras, two near-infrared cameras, a visible camera, and a visible radiometer. The instruments can detect traces of organics, hydrocarbons, hydrated minerals, water ice, and water vapor. More details about the LCROSS scientific payload can be found on LCROSS mission page.

I wonder to what extent the debris caused by the impact of Centaur and LCROSS will interfere with the scientific instruments onboard LRO and Chandrayaan-1. Both LRO and Chandrayaan-1 will be orbiting the Moon on polar orbits at that time.

We presented in a previous post the Lunar Reconnaissance Orbiter (LRO) mission. The goals of the LRO mission are to map the lunar resources and to create a detailed 3D map of the lunar surface in preparation for future NASA missions to the Moon. However, NASA is not the only space agency that has high hopes regarding the exploration of the Moon. The Indian Space Research Organization (ISRO) is another agency heavily involved in space activities.

Credits: ISRO

Interest in undertaking a lunar scientific mission was sparked at a meeting of the Indian Academy of Sciences in 1999. One year later, the Astronautical Society of India made a recommendation supporting the idea.

The ISRO formed a National Lunar Mission Task Force that involved leading Indian scientists. The Task Force provided an assessment on the feasibility of such a mission. The mission, called Chandrayaan-1, was approved in November 2003 for an estimated cost of $83 million USD.

The Chandrayaan-1 spacecraft is a 1.5 meter cube with a weight mass of approximately 523 kg. The spacecraft bus is based on an already developed meteorological satellite. Chandrayaan-1 will carry a 30 kg probe that will be released to penetrate the lunar surface. The power for the onboard systems is generated by a solar panel. The 750 watts generated by the solar panel will be stored by the rechargeable batteries onboard the spacecraft. Maneuvering in the lunar orbit is done using a bipropellant propulsion system.

Credits: ISRO

The scientific payload contains a diverse collection of instruments. The instruments were designed and developed by ISRO, ESA, NASA, and the Bulgarian Space Agency.

There are two instruments that will map the surface of the Moon: the Terrain Mapping Camera (TMC) will produce a 5 meter resolution map of the surface, and the Lunar Laser Ranging Instrument (LLRI) will scan the lunar surface and determine the surface topography.

The X-ray spectrometer onboard the spacecraft has three components: the Imaging X-ray Spectrometer (CIXS), the High Energy X-ray/gamma ray spectrometer (HEX), and the Solar X-ray Monitor (SXM). The X-ray spectrometer will measure the concentration of certain elements on the lunar surface as well as monitor the solar flux in order to normalize the results of the measurements taken.

The mineralogical configuration of the surface will be mapped by four instruments: the Hyper Spectral Imager (HySI), the Sub-keV Atom Reflecting Analyzer (SARA), the Moon Mineralogy Mapper (M3), and the Near-Infrared Spectrometer (SIR-2).

The Radiation Dose Monitor (RADOM-7) will record the radiation levels in the lunar orbit.

Credits: ISRO

ISRO has two operational launch vehicles: the Polar Satellite Launch Vehicle (PSLV) and the Geosynchronous Satellite Launch Vehicle (GSLV). For Chandrayaan-1, ISRO has chosen to use PSLV as a launch vehicle. The PSLV developmental flights were completed in 1996 and the rocket has had 12 successful missions since then. PSLV is 44.43 meters tall and has a weight of 294 tonnes at launch. It can inject a payload of 1,000 kg – 1,200 kg into a polar orbit.

The launch of the Chandrayaan-1 mission is scheduled for the end of October 2008. The PSLV rocket will take off from the Satish Dhawan Space Center in Sriharikota on the southeast coast of India. The transfer to the lunar orbit will take approximately five days and after additional maneuvers the spacecraft will reach its final polar orbit, 100 km above the surface. The spacecraft will be operational for two years.

The Chandrayaan-1 mission opens the door to future lunar missions. ISRO has already committed to a second Chandrayaan mission that will land a rover on the surface of the Moon. The rover will perform a number of experiments on the lunar surface and the results will be relayed to Earth by the Chandrayaan-2 orbiter.

We will come back with more details about the Chandrayaan-1 mission as the events unfold. Please stay tuned on the OrbitalHub frequency.