UPSC Essentials: One word a day- CAPSTONE

Subject: Science and Technology, Space

What is CAPSTONE?

The Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE), is a CubeSat Mission of NASA. It is going to be what NASA calls a “pathfinder mission” for the Gateway – an orbiting outpost (part of NASA’s Artemis program) that astronauts will visit before descending to the surface of the Moon.

Note: CubeSats are a class of nanosatellites that use a standard size and form factor. The standard CubeSat size uses a “one unit” or “1U” measuring 10x10x10 cm and is extendable to larger sizes; 1.5, 2, 3, 6, and even 12U.

What is unique about the CAPSTONE mission?

The CAPSTONE is approximately the size of a small microwave oven. According to NASA, it is expected to be the first-ever spacecraft to operate in a near rectilinear halo orbit around the Moon. In this particular orbit, the agency said that the CubeSat will pass as close as 1,000 miles and as far as 43,500 miles from the surface of the Moon.

Note: A near rectilinear halo orbit (NRHO), is significantly elongated. Its location is at a precise balance point in the gravitational pulls of Earth and the Moon. It thus offers stability for long-term missions like Gateway and requires minimal energy to maintain.

How will the CAPSTONE mission be useful for space missions?

The CAPSTONE will be demonstrating how to enter into and operate in this unique orbit (rectilinear halo orbit) as well as test a new navigation capability. This particular information will help in reducing the logistical uncertainty for Gateway while ensuring that NASA and international partners have safe access to the surface of the Moon. This will also provide a platform for science and technology demonstrations.

It will provide NASA and its partners with important insights to support the exploration of the Moon and Mars, including demonstration of spacecraft-to-spacecraft navigation services, verification of near rectilinear halo orbit characteristics for future spacecraft, and experience entering this orbit with a highly efficient lunar transfer, and more.

How is LRO linked to CAPSTONE?

NASA’s Lunar Reconnaissance Orbiter (LRO) will serve as a reference point for CAPSTONE. The intention is for CAPSTONE to communicate directly with LRO. CAPSTONE thus will utilize the data obtained from this crosslink to measure how far it is from LRO and how fast the distance between the two changes, which in turn determines CAPSTONE’s position in space.

What are the objectives of the CAPSTONE Mission?

The objectives of the CAPSTONE Mission are:

1) Verify the characteristics of a cis-lunar near rectilinear halo orbit for future spacecraft

2) Demonstrate entering and maintaining this unique orbit that provides a highly-efficient path to the Moon’s surface and back

3) Demonstrate spacecraft-to-spacecraft navigation services that allow future spacecraft to determine their location relative to the Moon

without relying exclusively on tracking from Earth

4) Lay a foundation for commercial support of future lunar operations

5) Gain experience with small dedicated launches of CubeSats beyond low-Earth orbit, to the Moon, and beyond

Point to ponder: How is CubeSat different from SmallSat? What is the current status of the CAPSTONE mission? What is NASA’s Artemis program?

(sources: nasa.gov, scitechdaily.com)