SPACECRAFT-BASED DEPLOYABLE SOLAR CONCENTRATOR FOR GASIFYING CRYOGENIC LIQUIDS
A solar collector system that is storable and deployable on a space vehicle is disclosed. Such a system may be used for generating electricity from solar energy or for collecting heat for converting a cryogenic liquid to its gas phase. The solar collector system may include a reflective solar collector membrane, an attachment to connect portions of the reflective solar collector membrane to the space vehicle, and a winch and tether system on the space vehicle for holding the reflective solar collector membrane in a closed state that wraps around the space vehicle or for holding the reflective solar collector membrane in a parabolic cylindrical shape in an open state. In the closed state, the reflective solar collector membrane may be configured to insulate the space vehicle from solar radiation.
1 . A solar collector system that is storable and deployable on a space vehicle, the system comprising:
a reflective solar collector membrane having a first edge, a second edge, and a central axis between and in parallel with both the first edge and the second edge;
an attachment to connect the central axis of the reflective solar collector membrane to the space vehicle;
a first spreader bar on the first edge and a second spreader bar on the second edge; and
a winch and tether system on the space vehicle, wherein the winch and tether system is configured to place the first spreader bar and the second spreader bar in i) a first configuration that maintains the reflective solar collector membrane in a closed state that wraps around the space vehicle and ii) a second configuration that maintains the reflective solar collector membrane as a parabolic cylinder in an open state and positioned on a single side of the space vehicle.
2 . The system of claim 1 , further comprising multiple flexible ribs embedded in the reflective solar collector membrane to provide resilience to the reflective solar collector membrane and to i) connect the first spreader bar and the second spreader bar together via the attachment or ii) connect each of the first spreader bar and the second spreader bar to the attachment.
3 . The system of claim 2 , wherein the multiple flexible ribs comprise a superelastic alloy that pulls the reflective solar collector membrane into a parabolic cylinder shape in the open state.
4 . The system of claim 1 , wherein in the closed state, the reflective solar collector membrane is configured to insulate the space vehicle from solar radiation.
5 . The system of claim 1 , further comprising a conduit configured to carry a fluid to absorb solar energy reflected from the reflective solar collector membrane, wherein the conduit is located at a focal line of the reflective solar collector membrane in the open state.
6 . The system of claim 5 , wherein the conduit is configured to carry the fluid through a thermal exchange system onboard the space vehicle.
7 . The system of claim 6 , wherein the thermal exchange system is configured to heat a cryogenic liquid to a gas phase by using the absorbed solar energy in the heat transfer fluid.
8 . The system of claim 5 , further comprising telescoping rods to connect the conduit to the attachment, wherein the telescoping rods are configured to extend during a transition from the closed state to the open state.
9 . A system for gasifying a cryogenic fluid in a space vehicle using solar energy, the system comprising:
a first storage tank to contain the cryogenic fluid;
a second storage tank to contain gas produced from the cryogenic fluid;
a heat exchanger;
tubing configured to carry the cryogenic fluid from the first storage tank, through the heat exchanger, and to the second storage tank;
a reflective solar collector located external to the space vehicle; and
a conduit positioned along a focal line of the reflective solar collector and configured for circulating a heat transfer fluid through the heat exchanger, which is configured to convey heat from the heat transfer fluid to the cryogenic fluid in the tubing.
10 . The system of claim 9 , wherein the reflective solar collector is configured to be in a closed state or an open state, wherein the reflective solar collector is wrapped at least partially around the space vehicle in the closed state and the reflective solar collector is a parabolic cylinder extending from the space vehicle in the open state.
11 . The system of claim 10 , wherein the reflective solar collector comprises:
a reflective membrane having a first edge, a second edge, and a central axis between and in parallel with both the first edge and the second edge; and
a first spreader bar on the first edge and a second spreader bar on the second edge, and wherein the system further comprises:
an attachment to connect the central axis of the reflective membrane to the space vehicle; and
a winch and tether system on the space vehicle, wherein the winch and tether system is configured to place the first spreader bar and the second spreader bar in a first configuration corresponding to the closed state or a second configuration corresponding to the open state.
12 . The system of claim 11 , wherein the reflective solar collector further comprises multiple flexible ribs embedded in the reflective membrane to provide resilience to the reflective membrane and to i) connect the first spreader bar and the second spreader bar together via the attachment or ii) connect each of the first spreader bar and the second spreader bar to the attachment.
13 . The system of claim 12 , wherein the multiple flexible ribs comprise a superelastic alloy that pulls the reflective membrane into a parabolic cylinder shape in the open state.
14 . The system of claim 11 , wherein in the closed state, the reflective membrane is configured to insulate the space vehicle from solar radiation.
15 . The system of claim 11 , further comprising telescoping rods to connect the conduit to the attachment.
16 . A method for gasifying a cryogenic fluid in a space vehicle using solar energy, the method comprising:
collecting solar heat from a reflective solar collector into a heat transfer fluid in a conduit that is in a focal region of the reflective solar collector, wherein the reflective solar collector and the conduit are located external to the space vehicle;
circulating the heat transfer fluid through a heat exchanger in the space vehicle;
drawing the cryogenic fluid from a storage tank into the heat exchanger;
allowing the heat exchanger to heat the cryogenic fluid using the solar heat in the heat transfer fluid; and
storing a gas resulting from the heating of the cryogenic fluid.
17 . The method of claim 16 , wherein the reflective solar collector is a parabolic cylinder and the focal region is a focal line of the parabolic cylinder.
18 . The method of claim 17 , wherein the reflective solar collector comprises i) a reflective membrane having a first edge, a second edge, and a central axis between and in parallel with both the first edge and the second edge, and ii) a first spreader bar on the first edge and a second spreader bar on the second edge, and
wherein the method further comprises controlling positions of the first and the second spreader bars to form and maintain the reflective membrane in the parabolic cylinder shape or to wrap the reflective membrane at least partially around the space vehicle for storage or for adding insulation to the space vehicle.
19 . The method of claim 18 , wherein controlling the positions of the first and the second spreader bars comprises operating a winch and tether system on the space vehicle, wherein the winch and tether system is configured to place the first spreader bar and the second spreader bar in i) a first configuration corresponding to the reflective membrane having the parabolic cylinder shape or ii) a second configuration corresponding to the reflective membrane being wrapped at least partially around the space vehicle.
20 . The method of claim 16 , further comprising, before collecting the solar heat from the reflective solar collector, stowing the reflective solar collector within a fairing and at least partially wrapped around a fuel tank of the space vehicle during launch of the space vehicle from Earth.