Thursday, December 22, 2011

A Vital Cislunar Space Application: Satellite Servicing

In my discussion of the Flexible Path to the Moon, I emphasized the importance of cislunar space.  My view is that developing infrastructure and capabilities in cislunar space is crucial to sustainable and affordable astronaut exploration to more distant destinations like the lunar surface, NEAs, and Mars, and is also vital to enabling exploration efforts to deliver near-term benefits to the taxpayer.  A number of articles have recently appeared that highlight the promise of cislunar space, such as Accelerating the future: human achievements beyond LEO within a decade (The Space Review), Exploration Gateway Platform hosting Reusable Lunar Lander proposed (, and Phase II of “Asteroid Next” missions: Proving Grounds for future crewed Mars missions (also  These have generated considerable interest and discussion, and it would be fun to add my voice to those discussions.

But I'm not going to do that.

Instead, I'd like to focus on a part of the Conference Report for H.R. 2112, the bill that funds NASA for the next fiscal year.  The following excerpt is from the report's Space Technology section:

Satellite servicing.—The conference agreement provides no less than $25,000,000 for satellite servicing activities. This funding will contribute to the planned competitive satellite servicing demonstration mission and shall be managed by the Human Exploration and Operations (HEO) Mission Directorate.

This $25M (at least) is part of the $575M for Space Technology. 

The following excerpt is from the report's Space Operations section:

Satellite servicing.—The conference agreement includes $50,000,000 from Space Operations to continue satellite servicing activities. These funds are in addition to $25,000,000 for satellite servicing in the Space Technology account. The HEO Mission Directorate shall continue to be responsible for the overall direction and management of all agency satellite servicing activities, which are undertaken as a joint project of the HEO, Space Technology and Science mission directorates. Satellite servicing activities shall include mission architecture design, robotic system development, autonomous rendezvous and capture sensor testing, fluid transfer demonstrations and spacecraft design.

Funds are to be used to continue work on a competitive project to develop, in collaboration with a U.S. commercial partner, a satellite servicing mission capable of operating in geosynchronous Earth orbit. The goal for such a mission is to achieve an on-orbit servicing of an observatory-class government satellite by 2016. Any U.S. commercial partner should be willing to invest its own resources in this mission, as it is intended to foster the creation of an ongoing commercial capability that could meet the needs of NASA, other Federal agencies, the commercial satellite sector and the scientific community.

The funds are for a satellite servicing mission involving NASA and a commercial partner with skin in the game operating in geosynchronous orbit.  Demonstration of such a commercial capability could be an important step in opening new robotic commercial satellite servicing markets in cislunar space, and could even lead later to development of human satellite servicing markets there.  Creation of such self-sustaining economic capabilities represents an important milestone in the development of cislunar space, and could be an important step in enabling sustainable exploration and development of more difficult destinations like the lunar surface and NEAs.

The most immediate activity of the NASA Satellite Servicing Capabilities Office is the Robotic Refueling Mission on the International Space Station.  This mission demonstrates robotic technologies to refuel, repair, and otherwise service satellites using various tools.  The office is also investigating a Robotic Servicing Mission.  This would be a robotic mission to demonstrate actual servicing for one or more GEO satellites. 

NASA has released an RFI for development of an on-orbit robotic servicing capability for spacecraft.  In this RFI, NASA shows its interest in a public-private partnership where it uses its satellite servicing capabilities and experience with a commercial partner:

NASA does not intend to establish a Government operated on-orbit satellite servicing capacity but rather to foster the creation of a domestic capability which may meet both future Government and non-government needs. Satellite servicing capabilities may include satellite recovery, repair, relocation, refueling, inspection, subsystem or component replacement, or other services that extend the life or capabilities of on-orbit assets.

The detailed RFI (PDF) gives several examples of the types of partnerships that NASA might be interested in pursuing with private industry.  The RFI makes it clear that the envisioned mission is a robotic one to GEO (as opposed, for example, to a mission where GEO satellites are delivered to and from servicing robots and/or astronauts in LEO), even though Congress's direction is that NASA's HEO Mission Directorate will be in charge of NASA's overall satellite servicing effort.  The RFI lists several contributions that NASA might make to the effort, such as satellite servicing patents, tools for repair, refueling, and other servicing jobs, autonomous rendezvous capability, sensors, test labs, operations support, computer resources, and more.

The RFI suggests several potential types of public-private partnerships.  In one partnership model, the commercial partner owns and is responsible for the servicing hardware while the government provides some of the contributions just described as well as an initial satellite to service.  In another model, the government pays a fixed price for commercial services, with both partners contributing hardware and support.  The commercial partner could rent the servicing vehicle for additional servicing missions beyond the government satellites.  In a third model, the commercial partner would be responsible for the entire system, and NASA would not identify a government satellite to service, but could provide intellectual property to the commercial partner.  Other models can be considered.

Several questions and responses (PDF) related to the RFI have also been published.  Some of these deal with foreign participation.  This is not surprising, since MDA is interested in and concerned about the NASA satellite servicing mission. 

Meanwhile, the First Community Workshop on Assessing Capabilities for Human Operations in Cis-Lunar Space: What's Possible Now? includes a presentation on a Manned GEO Servicing Study (PDF) involving NASA and DARPA.  Different satellite servicing missions by astronauts in GEO that would be useful in and of themselves while preparing NASA for future, more distant exploration missions are presented.  Missions could include habitat nodes and tugs to move satellites.  

DARPA has also presented the PHOENIX workshops on a potential satellite servicing program:

The goal of the Phoenix program is to develop and demonstrate technologies to cooperatively harvest and re-use valuable components from retired, nonworking satellites in GEO ...

 There are multiple components in the Phoenix architecture.  Nanosatellites would be launched as secondary payloads.  A satellite servicing component would robotically attach the nanosatellites to an antenna of a dead satellite, enabling the large antenna to be reused.  The nanosatellites are delivered in a new PODS nanosatellite delivery module.  This PODS delivery mechanism meets with the satellite servicing component which can then use the nanosatellites and tools in the PODS as a sort of tool chest.

Like robotic precursor missions to the Moon, NEAs, or Mars, a commercial GEO robotic satellite servicing mission can help set the stage for more ambitious future astronaut servicing missions in the same type of location.  A commercial robotic satellite servicing mission done in partnership with NASA can also strengthen the U.S. commercial spaceflight industry, much like NASA's current approach to send cargo and later crew to the ISS using commercial services.  A commercial robotic satellite servicing mission can demonstrate some of the technologies and capabilities needed by NASA to productively and safely send astronauts to more distant destinations like Lagrange points, the lunar surface, NEAs, and Mars and its moons.  This is especially true of missions that leverage robotic capabilities like telerobotics.  Finally, a commercial GEO robotic satellite servicing mission that involves satellite refueling can develop new markets for fuel that could later come from locations like the lunar surface, thus creating an opportunity for the type of exploration and development using ISRU that can create a strong space economy.

For more information:

On-Orbit Satellite Servicing Study - Project Report - comprehensive 2010 NASA satellite servicing workshop report, including a history of satellite servicing and several potential servicing missions from basic robotic satellite servicing to astronaut assembly and maintenance of large observatories

SSCO - NASA Satellite Servicing Capabilities Office

NASA_SatServ - Twitter account for the NASA Satellite Servicing Capabilities Office

The Future of On-Orbit Satellite Servicing - SpaceRef Forum (article from the September 2011 Space Quarterly (PDF)) - This gives a good overview of the history and recent state of satellite servicing.

Robot Surgeon Tech Aims to Fix NASA Satellites -

Medical Robotics Experts Help Advance NASA’s ‘Satellite Surgery’ Project - Johns Hopkins University

Frank Cepollina, Deputy Associate Director, Space Servicing Capabilities Office, NASA Goddard Space Flight Center - Space News - This covers the Robotic Refueling Mission, a satellite servicing test on Earth, and the potential servicing mission in GEO.

NASA Selects First Payloads For Upcoming Reduced-Gravity Flights - NASA - This includes a Zero-G flight for the Autonomous Robotic Capture payload, similar to the Approach, Rendezvous and Capture Demonstration Cepollina mentioned in the previous article.