Reentry Plasma Onset and Emergence Sensor

Navy SBIR 24.2 - Topic N242-101
SSP - Strategic Systems Programs
Pre-release 4/17/24   Opened to accept proposals 5/15/24   Closes 6/12/24 12:00pm ET    [ View Q&A ]

N242-101 TITLE: Reentry Plasma Onset and Emergence Sensor

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Hypersonics; Nuclear; Space Technology

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.

OBJECTIVE: Develop a sensor that can determine the onset of, and emergence from, a plasma environment which precludes the send and receipt of telemetry signals during ballistic reentry.

DESCRIPTION: Plasma environments generated by ballistic reentry conditions prevent the transmission of signals between the test article and ground receiving sites. To mitigate this, pre-flight analysis is conducted using empirical data and previous flight test observations to predict onset and emergence times, and these delays are programmed into the test article with margin on each side of the blackout window. This process artificially restricts the amount of telemetry data that can be transmitted from the test article, and is difficult to adapt to new conditions that do not match previous test conditions or otherwise violate the empirical data assumptions.

Maximizing the time telemetry is transmitted before onset of the blackout period and after emergence will have a significant impact on the total value of the test event and ability to leverage the data collected to improve the next experiment. This sensor will not only need to characterize the environments in real time, but also be capable of communicating with the existing telemetry infrastructure and surviving both space and ballistic reentry environments. Market research has not discovered a package that currently meets all of these requirements, so development will be required to fulfill the technical requirements while meeting packaging, communication, and survivability constraints. A final, test-ready product at the conclusion of Phase III should be capable of withstanding the proton environment of the South Atlantic Anomaly, shock environments of 3000 G, acceleration environments of ±80 G, and pressure environments of 75 PSIA.

Work produced in Phase II may become classified. Note: The prospective contractor(s) must be U.S. owned and operated with no foreign influence as defined by 32 U.S.C. § 2004.20 et seq., National Industrial Security Program Executive agent and Operating Manual, unless acceptable mitigating procedures can and have been implemented and approved by the Defense Counterintelligence and Security Agency (DCSA) formerly Defense Security Service (DSS). The selected contractor must be able to acquire and maintain at least a secret level facility and Personnel Security Clearances. This will allow contractor personnel to perform on advanced phases of this project as set forth by DCSA and SSP in order to gain access to classified information pertaining to the national defense of the United States and its allies; this will be an inherent requirement. The selected company will be required to safeguard classified material during the advanced phases of this contract IAW the National Industrial Security Program Operating Manual (NISPOM), which can be found at Title 32, Part 2004.20 of the Code of Federal Regulations.

PHASE I: Demonstrate capability to characterize a plasma environment in real time, and the ability to communicate with an external controller at defined set points representative of blackout conditions. The concept should show a path to meeting final size, weight, and power requirements necessary for integration into a Navy flight test vehicle. Feasibility should be communicated by a combination of research white papers, bills of materials, drawings, and simulations. The Phase I Option, if exercised, will include the initial design specifications and capabilities description to build a prototype solution in Phase II.

PHASE II: Build and evaluate a prototype sensor for compatibility with Navy reentry flight test architecture. Demonstration in a relevant plasma environment is preferred, but in the case that a test facility cannot be identified during the Phase II period of performance, surrogate testing which demonstrates the proof of concept while identifying the areas where results are not representative is acceptable. The prototype will be required to measure the environment, demonstrate communication with an external controller, and send a signal to stop and restart a signal at the proper times correlated with the ability to send and receive a signal. If representative testing cannot be accomplished by the end of the Phase II period of performance, two prototype sensors will be required at the conclusion of the effort for future test opportunities.

It is probable that the work under this effort will be classified under Phase II (see Description section for details).

PHASE III DUAL USE APPLICATIONS: The final product should meet size, weight, and power requirements such that it is fully capable of integrating with a Navy ballistic flight test body. It will be capable of surviving launch, space, and reentry environmental requirements. In addition to fully performing the real-time plasma characterization mission, it should also fully integrate with the telemetry architecture to provide usable inputs for starting the delay process. This will be used on both developmental and surveillance Navy test reentry bodies undergoing end-to-end ballistic testing, and will greatly enhance the ability to transmit the data characterized by each test event for use in further development or in-service assessment. Once integrated into the final test capsule, the full flight test body will undergo environmental and functional testing to ensure all components are performing together as expected.

Plasma blackout conditions exist in any high temperature environment where communication between a vehicle and ground receiving sites is required. Examples of this include the reentry of crewed space missions as well as any future hypersonic aircraft exceeding Mach 10, where the rapid reacquisition of communication can play an important role.


  1. Sawicki, Pawel. "Radio Communications Blackout." University of Colorado Boulder Nonequilibrium Gas & Plasma Dynamics Laboratory, 2021. 31 August 2023.
  2. Webb, Bruce and Ziolkowski, Richard. "Metamaterial-Inspired Multilayered Structures Optimized To Enable Wireless Communications Through A Plasmasonic Region." Applied Physics Letters, Volume 118, Issue 9, 1 March 2021.
  3. Li, Jianfei, Wang, Ying, et al. "Experimental observations of communication in blackout, topological waveguiding and Dirac zZero-index property in plasma sheath." Nanophotonics, vol. 12, no. 10, 2023, pp. 1847-1856.

KEYWORDS: Plasma Blackout; Communications Blackout; Ballistic Reentry; Plasma Sheath; Atmospheric Reentry; Radio Blackouts; Ionization Blackouts


The Navy Topic above is an "unofficial" copy from the Navy Topics in the DoD 24.2 SBIR BAA. Please see the official DoD Topic website at for any updates.

The DoD issued its Navy 24.2 SBIR Topics pre-release on April 17, 2024 which opens to receive proposals on May 15, 2024, and closes June 12, 2024 (12:00pm ET).

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Topic Q & A

5/31/24  Q. The plasma created by the hypersonic re-entry speed creates a difficulty for vehicle transmitters to radiate sufficient RF energy to overcome the energy absorption characteristics of the ensuing plasma. As stated in the requirement, analytical techniques are currently used to predict the onset of the plasma and the subsequent dissipation of same to shut down the transmission. The analysis does not create absolute timing for the presence and absence of RF blocking plasma. Thus, transmitter management results in early anticipation of the onset of plasma and late estimates of the dissipation. It appears that the justification for the development of a plasma detector is to reduce the “guard band” timing of transmission control to an absolute minimum to obtain maximum air to ground data transmission. There is no reason to believe that the plasma would damage the transmitter. Why is there a need to control the transmitter and shut it down during the plasma period? Is it possible that the detector would be used to trigger data recorders that would buffer data otherwise lost in the blockage of RF transmission?
If so, is there an inherent requirement in this program for a data recorder? In another Q&A answer, the government suggests that if the contractor has an RF transmission scheme that would effectively transmit through the plasma, that such a proposal would be considered of value in the competitive analysis process? If this is true, the design of an RF transmission scheme (frequency and modulation control) is an additive requirement over and above simple detection and the presence and absence of plasma? Would this addition to a proposal increase the chances of award?
   A. There is concern about energy reflection back into the transmitter due to a plasma environment degrading or destroying the equipment.
Yes, this is how the system works now, but with the pre-flight analysis driving the buffer timing.
No, this already exists.
Frequency and modulation scheme cannot dynamically change during flight due to the ground collection equipment. A transmission scheme compatible with existing systems that mitigates the impact of transmission blackout is of value if it meets the overall stated goal of increasing the data received at the ground station.
N/A (response provided for final question).
5/21/24  Q. Hi authors, I wanted to confirm that the solicitation is for a sensor to detect the reentry plasma communications blackout onset, not to demonstrate radio communications that overcome the blackout? Thanks in advance.
   A. Yes, the solicitation is for a sensor to use in conjunction with an already approved transmitter and telemetry system. If a radio communication method that overcomes blackout can be proposed and demonstrated however, that would meet the same final technical objective. The current limitations of the transmitter are: S-Band for frequency, 10-15W power, 0.768-5.12 Mbps
5/21/24  Q. 1. Will there be a dielectric window on the test vehicle that allows passage/transmission of electromagnetic radiation to a sensor positioned inside the vehicle?
2. What is defined by the ability for external communication. Does this mean that the sensor has the ability to analyze measurements in real time and then determine when to communicate over a serial-type interface to another system inside the test article?
3. Is there a lower threshold for the detection of the plasma environment? Is there a minimum electron density, or just the minimum necessary to allow communication at common bands?
4. Does the system need to detect the plasma environment over the entire vehicle or just the window region?
5. Is there a number (or range) for the available power for the system that you can provide?
   A. 1. Yes
2. Yes, that is a good interpretation of the ask. External communication is defined by closing the telemetry link from the body to a ground receiving station. Communication to other systems within the test article should occur using Spacewire protocols
3. Minimum necessary to allow communication at S-Band
4. Just the window region
5. S-Band for frequency, 10-15W power, 0.768-5.12 Mbps
05/17/24  Q. 1) Will sensors need to be flushed out on the vehicle surface? Would a protrusion like < 2 mm be acceptable?
2) Is the vehicle surface conductive?
3) Density - how fast do we need to sample to be able to detect the radio blackout?
4) Is there any preference where this probe should be located on the test body?
5) Any SWaP limitations (Size, Weight, and Power) for the sensor
6) Are there limitations on interface points? Number of electrical / comms / structural interface points with the vehicle?
   A. 1) Sensor will need to be interior to the body or flush to the surface. If flush to the surface, the contractor will be responsible for protecting it from thermal environment and ensuring the integrity of the rest of the vehicle
2) Will not answer in this environment
3) The sensor should have 95% reliability in enveloped environments. It should communicate blackout onset and emergence to the telemetry system within 0.1 seconds of determining the conditions with an accuracy of 98%.
4) No
5) The sensor should be compatible with SpaceWire communication protocols, and require no more than 28V power. There is no size requirement for Phase I, but should have a path to a size no larger than 6.0" x 5.25" x 2.0". The smaller, lighter, and less power required at the final product, the better
6) No limitations for Phase I. If selected for Phase II, further integration efforts with the rest of the telemetry system will be pursued

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