Responses to March 25 Opening Session Questions

Please see below for answers to WebEx ‘chat’ questions asked over the course of the March 25 opening session.

Question 1:  

Flexibility sounds great, but is often counter to science goals.  (For example, there just isn't much flexibility in an interplanetary destination...)  How does the rideshare office suggest missions be flexible if the science goals are specific or at least limit the choices?  

Answer 1:   

Great Question!  Flexibility doesn’t necessarily mean that your science goals themselves need to be flexible, but its more about being flexible in how you achieve those same goals.   It’s knowing where your mission can and where your mission can’t do your science with the instruments you have, not just where it is optimal to do the science or at the exact orbit it was designed for.   For example, can you meet you level 1 requirements from only a sun synch orbit with a very specific ascending node…. Or can you also meet your level 1’s from multiple ascending nodes with the capability of drifting or from a different LEO orbit?

With interplanetary missions, it may be more difficult to be ‘flexible’ with science goal destinations. However, the flexibility in the spacecraft bus/propulsion system may allow the RPL to get themselves to their desired science location from multiple primary mission launch targets.  

ESCAPADE is a great example of a mission exhibiting the flexibility to be successful as a rideshare.   After being de-manifested from their primary ‘ride’, ESCAPADE changed their propulsion system, and can now potentially achieve arriving at Mars from a LEO insertion, instead of only being able to be launched into a very specific high energy trajectory.  This allows for flexibility to be matched up with more frequent launch opportunities.

Question 2:

HFORT program has funded many low-earth orbit CubeSat missions. I am curious if HFORT program is willing to fund a CubeSat mission beyond the LEO orbit, (for example, geosynchronous orbit). If there's a concern, would you share with us?

Answer 2:

In response to the question about HFORT and orbits beyond LEO. The problem is the availability of affordable RideShare opportunities and the issue of de-orbiting missions after completion. CuSP is an HFORT investigation using the Artemis-1 CubeSat opportunity to achieve a deep space orbit. The delays in launch and the requirements creep makes future launch via SLS a difficult sell for HFORT. The initial HFORT attempt to fly GTOSat to a GTO orbit has met with severe complications - particularly in the requirements to de-orbit and avoid generating more "space debris." The market forces have reduced the number of GEO opportunities relative to expectations of 5 years ago. The only HPD CubeSat mission for GEO is an Explorers MO: SunRISE. The SunRISE mission orbit is actually located in the disposal orbit for GEO. The investigation independently obtained the launch opportunity. In conclusion, at the current point of time, it is very difficult for a HFORT proposal to be competitive beyond LEO without a very specific pre-planning for launch opportunities and mitigation of potential for space debris.

Question 3:

Is there a follow-on to AstroBee? perhaps in a space environment?

Answer 3:

It's still early days for AstroBee, so there's not a specific follow-on as yet; there's considerable interest across several NASA centers to do a comparable external system!