| 1. |
- Farnocchia, Davide, et al.
(författare)
-
The Second International Asteroid Warning Network Timing Campaign: 2005 LW3
- 2023
-
Ingår i: The Planetary Science Journal. - : Institute of Physics (IOP). - 2632-3338. ; 4:11
-
Tidskriftsartikel (refereegranskat)abstract
- The Earth close approach of near-Earth asteroid 2005 LW3 on 2022 November 23 represented a good opportunity for a second observing campaign to test the timing accuracy of astrometric observation. With 82 participating stations, the International Asteroid Warning Network collected 1046 observations of 2005 LW3 around the time of the close approach. Compared to the previous timing campaign targeting 2019 XS, some individual observers were able to significantly improve the accuracy of their reported observation times. In particular, U.S. surveys achieved good timing performance. However, no broad, systematic improvement was achieved compared to the previous campaign, with an overall negative bias persisting among the different observers. The calibration of observing times and the mitigation of timing errors should be important future considerations for observers and orbit computers, respectively.
|
|
| 2. |
- Beck, R., et al.
(författare)
-
GPSDTN : Predictive velocity-enabled delay-tolerant networks for arctic research and sustainability
- 2007
-
Ingår i: Second International Conference on Internet Monitoring and Protection (ICIMP 2007). - Los Alamitos, Calif : IEEE Computer Society Press. - 9780769529110
-
Konferensbidrag (refereegranskat)abstract
- A Delay-Tolerant Network (DTN) is a necessity for communication nodes that may need to wait for long periods to form networks. The IETF Delay Tolerant Network Research Group is developing protocols to enable such networks for a broad variety of Earth and interplanetary applications. The Arctic would benefit from a predictive velocity-enabled version of DTN that would facilitate communications between sparse, ephemeral, often mobile and extremely power-limited nodes. We propose to augment DTN with power-aware, buffer-aware location- and time-based predictive routing for ad-hoc meshes to create networks that are inherently location and time (velocity) aware at the network level to support climate research, emergency services and rural education in the Arctic. On Earth, the primary source of location and universal time information for networks is the Global Positioning System (GPS). We refer to this Arctic velocity-enabled Delay-Tolerant Network protocol as "GPSDTN" accordingly. This paper describes our requirements analysis and general implementation strategy for GPSDTN to support Arctic research and sustainability efforts
|
|
| 3. |
- Jones, Geraint H., et al.
(författare)
-
The Comet Interceptor Mission
- 2024
-
Ingår i: Space Science Reviews. - : Springer Nature. - 0038-6308 .- 1572-9672. ; 220:1
-
Tidskriftsartikel (refereegranskat)abstract
- Here we describe the novel, multi-point Comet Interceptor mission. It is dedicated to the exploration of a little-processed long-period comet, possibly entering the inner Solar System for the first time, or to encounter an interstellar object originating at another star. The objectives of the mission are to address the following questions: What are the surface composition, shape, morphology, and structure of the target object? What is the composition of the gas and dust in the coma, its connection to the nucleus, and the nature of its interaction with the solar wind? The mission was proposed to the European Space Agency in 2018, and formally adopted by the agency in June 2022, for launch in 2029 together with the Ariel mission. Comet Interceptor will take advantage of the opportunity presented by ESA’s F-Class call for fast, flexible, low-cost missions to which it was proposed. The call required a launch to a halo orbit around the Sun-Earth L2 point. The mission can take advantage of this placement to wait for the discovery of a suitable comet reachable with its minimum Δ V capability of 600 ms − 1 . Comet Interceptor will be unique in encountering and studying, at a nominal closest approach distance of 1000 km, a comet that represents a near-pristine sample of material from the formation of the Solar System. It will also add a capability that no previous cometary mission has had, which is to deploy two sub-probes – B1, provided by the Japanese space agency, JAXA, and B2 – that will follow different trajectories through the coma. While the main probe passes at a nominal 1000 km distance, probes B1 and B2 will follow different chords through the coma at distances of 850 km and 400 km, respectively. The result will be unique, simultaneous, spatially resolved information of the 3-dimensional properties of the target comet and its interaction with the space environment. We present the mission’s science background leading to these objectives, as well as an overview of the scientific instruments, mission design, and schedule.
|
|
