XHAB TIM Questions

General Questions


Q: May I submit a proposal if I did not submit a notice of intent?

A: Yes, the notice of intent is encouraged but neither required nor binding.


Q: Can proposals for multiple projects be combined into one proposal?

A: Because a limited amount of project topics will be funded, the recommendation would be to put them in separately, but make sure to comment that the efforts would have additional collaboration value if combined. That way they would both receive more value from that evaluation factor and yet still stand alone. Each proposal is scored independently, and combining them might lead to both getting rejected because they were grouped together when one of them might have been a winner on its own.


Plant Anywhere: Plants Growing in Free Habitat Spaces:


Q: What sort of maintenance tasks, other than providing nutrients and water should be considered when designing the PlantBots?

A: Additional maintenance tasks could include harvesting, pruning, pollinating, removing debris like fallen leaves or pruned leaves and stems, and/or visual monitoring for expert evaluation. Focusing on just a few aspects is recommended due to the complexity of the operations.


Q: Are there any specific plants we should plan for because not all grow the same way?

A: Suitable plants are salad crops normally grown in containers like lettuce, strawberries, tomatoes, etc, or even super-dwarf tree varieties. The challenge is more about advancing the remote capability to support higher order plant growth; therefore, the chosen crop should be kept simple and choosing just one plant type is acceptable.


Q: Are there any specific nutrients to be used?

A: A liquid fertilizer or solid growth media with a time-release fertilizer would be acceptable.


Q: Are water and nutrients allowed to be pre-mixed as one solution to be transported via PlantBot?

A: Yes, they can be pre-mixed.


Q: One section in the document mentioned that crew interaction for planting is assumed, yet one purpose of this system is to allow time for plants to be grown before crew arrival. How do these two conditions work together?

A: Crew interaction for planting, harvesting, and Smartpot placement can be assumed. This allows for project to narrow the scope of the project to allow for a simpler system to focus on advancing the remote food production capabilities between crew visits. The scenario proposed would have a permanent remote station that has crew visiting it periodically. The initial startup of the system would need some additional remote deployment tasks, which is beyond the scope of this challenge.


Q:What levels of gravity will this system be expected to work under?

A:It should work with aid in 1-g for demonstration purposes. It is expected to work in lunar gravity. If the students can make it work in microgravity then that would be acceptable as well.


Q:Can it be assumed that the SmartPots are supplied with energy via wiring, or does a local power supply such as a battery pack need to be present?

A:Wiring can be assumed. Typical spacecraft available power is 28 VDC but not required.


In-situ Manufacturing Workstation:


Q:What is the specific voltage that will be available?

A:As mentioned above, typical spacecraft power is 28 VDC, but at this stage the manufacturing system will be a prototype that functions in 1-g, and has access to facility power (120-240 volts). Other arrangements are also possible.


Q:Will the current supplied be continuous or intermittent?

A:Continuous current will be available.


Q:How much current will be supplied?

A:Any design current within reason will be possible at this stage.


Q:How much should/can the deliverable be integrated structurally to the habitat?

A:That would depend on the proposed design or concept.


Q:Can the structure for the habitat be modified?

A:A logical reason for modifying the structure of the habitat would certainly be entertained. For example, creating a pressurized pass-through accessing an external (vacuum) e-beam additive manufacturing unit would require penetrating the pressure vessel. Other designs would definitely be possible.


Q:Does the printer need to operate in zero or low gravity?

A:The printer should operate in a range of gravities, including zero-g.


Q:What is the ideal size of the printing platform?

A:Many additive manufacturing units consist of print heads mounted on orthogonal axis positioning hardware that cover a specified work volume. Ideally the system would collapse flat when not in use, and deploy an adjustable volume when in use.


Q:What materials should the printer work with?

A:The ultimate wish list is anything and everything. However, as a minimum, the ability to manufacture small plastic tools, fittings, ducts, pipes, conduits, small enclosures, all the way to non-critical structural elements may be considered (recall the film “Apollo 13” where the crew must cobble together odd items on board to solve their problem – future crews should be able to print solutions on demand). Even more preferred may be metal elements that can work as structure both inside and outside the spacecraft – an ultimate goal would be to provide capability to manufacture elements on demand that are needed during the mission, such as structures, mobility systems, control systems, etc.


Q:What is the optimum overall size of the printer, both when it is folded away and expanded for use?

A:There is currently little precedent for in-space manufacturing, so anything goes.


Q:What kind of atmosphere does the printer need to operate in? Is it pressurized?

A:That is part of the design. Pressurized or non-pressurized enclosures may be designed with the system, or access to the outside vacuum can also be proposed.


Q:How much open source code can be used?

A:That is up to the X-Hab design team.


Q:What sort of stresses will the pieces printed be undergoing?

A:Since there is very little precedent for in-space manufacturing, near-term practical suggestions are welcome. Eventually it is assumed that all onboard systems and replacement parts will be capable of being manufactured on board the spacecraft.