Space domain awareness sensor and related methods and systems
A space domain awareness (SDA) system includes several sensor spacecraft, some in Earth orbit and others in cislunar space. Each sensor spacecraft can include a sensor payload of an active optical sensor (e.g., a laser emitter and laser detector) and an SDA processor. The processor detects, tracks, and characterizes resident space objects (RSOs) using the output from the active optical sensor. In some embodiments, the sensor payload also includes a passive optical sensor, an electromagnetic sensor, and/or a plasma sensor; the SDA processor can use the outputs of these optional additional sensors to detect, track, and characterize RSOs as well. It is also contemplated that the SDA system can include a plurality of debris capture spacecraft, each of which includes a debris impact pad that includes a series of shield and stuffing layers that respectively increase in density along an intercept direction.
1 . A space domain awareness (SDA) system, comprising:
a plurality of sensor spacecraft, each sensor spacecraft of the plurality of sensor spacecraft comprising:
an active optical sensor; and
an SDA processor configured to:
receive an output from the active optical sensor;
detect a resident space object (RSO) using the output from the active optical sensor;
compute a projected orbital trajectory of the RSO using the output from the active optical sensor; and
characterize the RSO using the output from the active optical sensor.
2 . The SDA system according to claim 1 , wherein the plurality of sensor spacecraft comprises a plurality of sensor spacecraft in equatorial low Earth orbit.
3 . The SDA system according to claim 2 , wherein the plurality of sensor spacecraft further comprises a first sensor spacecraft positioned at Lagrange point L4 and a second sensor spacecraft positioned at Lagrange point L5.
4 . The SDA system according to claim 1 , wherein the SDA processor is configured to characterize the RSO as an active spacecraft when an actual orbital trajectory of the RSO deviates from the projected orbital trajectory of the RSO by more than a preset threshold amount.
5 . The SDA system according to claim 1 , further comprising at least one additional sensor selected from the group consisting of passive optical sensors, electromagnetic sensors, and plasma sensors, and wherein the SDA processor is further configured to:
receive an output from the at least one additional sensor;
detect the RSO using the output from the active optical sensor and the output from the at least one additional sensor;
compute the projected orbital trajectory of the RSO using the output from the active optical sensor and the output from the at least one additional sensor; and
characterize the RSO using the output from the active optical sensor and the output from the at least one additional sensor.
6 . The SDA system according to claim 1 , wherein the active optical sensor comprises:
a laser emitter configured to emit a non-collimated laser beam to illuminate a volume of space containing the RSO; and
a laser detector configured to detect a reflection of the non-collimated laser beam from the RSO.
7 . The SDA system according to claim 1 , further comprising a plurality of debris capture spacecraft, wherein each debris capture spacecraft of the plurality of debris capture spacecraft includes at least one debris impact pad comprising:
a plurality of shield layers arranged in a series of planes, wherein the series of planes is non-parallel to an intercept direction,
wherein each shield layer of the plurality of shield layers has a respective density, and
wherein the respective densities of the plurality of shield layers increase along the intercept direction; and
a plurality of stuffing layers interposed between the plurality of shield layers,
wherein each stuffing layer of the plurality of stuffing layers has a respective density, and wherein the respective densities of the plurality of stuffing layers increase along the intercept direction.
8 . The SDA system according to claim 7 , wherein the plurality of stuffing layers comprises at least one aerogel layer, the at least one aerogel layer having a gradient density that increases in the intercept direction.
9 . A space domain awareness (SDA) sensor, comprising:
a laser emitter configured to emit a non-collimated laser beam to illuminate a volume of space containing a resident space object (RSO);
a laser detector configured to detect a reflection of the non-collimated laser beam from the RSO; and
an SDA processor in operable communication with the laser emitter and the laser detector and configured to compute a distance from the SDA sensor to the RSO.
10 . The SDA sensor according to claim 9 , wherein:
the laser emitter has a pulse frequency and is configured to emit a series of non-collimated laser beam pulses at the pulse frequency;
the non-collimated laser beam has a cone angle; and
the pulse frequency and the cone angle are selected such that the RSO will be within the volume of space for at least two successive beam pulses of the series of non-collimated laser beam pulses.
11 . The SDA sensor according to claim 10 , wherein the SDA processor is further configured to compute a velocity of the RSO.
12 . The SDA sensor according to claim 10 , further comprising an optical detector configured to capture an optical image of the RSO when the volume of space is illuminated by the non-collimated laser beam.
13 . An apparatus for capturing a resident space object (RSO), the apparatus comprising:
a plurality of shield layers arranged in a series of planes, wherein the series of planes is non-parallel to an intercept direction,
wherein each shield layer of the plurality of shield layers has a respective density, and
wherein the respective densities of the plurality of shield layers increase along the intercept direction.
14 . The apparatus according to claim 13 , wherein each shield layer of the plurality of shield layers has a respective thickness, and the respective thicknesses of the plurality of shield layers increases along the intercept direction.
15 . The apparatus according to claim 13 , further comprising a plurality of stuffing layers interposed between the plurality of shield layers.
16 . The apparatus according to claim 15 , wherein each stuffing layer of the plurality of stuffing layers has a respective density, and wherein the respective densities of the plurality of stuffing layers increase along the intercept direction.
17 . The apparatus according to claim 15 , wherein at least one stuffing layer of the plurality of stuffing layers has a gradient density that increases along the intercept direction.
18 . The apparatus according to claim 15 , wherein the plurality of stuffing layers comprises an aerogel layer.
19 . The apparatus according to claim 13 , wherein the plurality of shield layers are spaced apart from each other along the intercept direction, and wherein a spacing between successive shield layers of the plurality of shield layers is configured to minimize spall ejecta from the apparatus when the RSO, traveling along the intercept direction, impacts the plurality of shield layers.
20 . An apparatus for capturing a resident space object (RSO), the apparatus comprising:
a first shield layer;
a second shield layer spaced apart from the first shield layer along an intercept direction;
a first stuffing layer between the first shield layer and the second shield layer;
a third shield layer spaced apart from the second shield layer along the intercept direction; and
a second stuffing layer between the second shield layer and the third shield layer;
wherein at least one of the first stuffing layer and the second stuffing layer comprises a gradient density aerogel oriented to have a density that increases along the intercept direction.