网帖翻译

According to Aviation Week, on July 21, on the eve of the opening of the 2024 Farnborough Air Show, Ella Carlsson, head of the Swedish Air Force Space Capabilities and Development Department, told reporters at the annual gathering of the Swedish Air Force Fan Club that the birth of the "Stella" project was largely influenced by the former director of the Ukrainian Space Agency. The former director once said that in the face of a country like Russia, in the event of a full-scale military conflict, if an aircraft can be used for the rapid emergency launch of satellites, it will bring significant help to the national strategy.

根据《航空周刊》报道，7月21日，在2024年范堡罗航展开幕前夕，瑞典空军太空能力和发展部门负责人埃拉·卡尔森（Ella Carlsson）在瑞典空军粉丝俱乐部（ Swedish Air Force Fan Club）的年度聚会上对记者表示，「斯特拉」项目的诞生很大程度上是受到乌克兰航天局前局长的影响。 该前局长曾表示，面对俄罗斯这样的国家，在可能爆发全面军事冲突的情况下，如果能够使用飞机进行卫星的快速紧急发射，将会为国家战略带来显著的帮助。

In fact, according to a report on the Swedish Broadcasting Corporation website, the Swedish Air Force has been considering launching satellites via the Gripen since September 2023. Carlsson has said that while it is currently possible to launch satellites at the Eslang Spaceport in the Arctic city of Kiruna, the Swedish military also wants to explore other options in case of war.

事实上，根据瑞典广播电台网站的报道，从2023年9月，瑞典空军就开始考虑通过鹰狮发射卫星。 卡尔森曾表示，虽然目前在北极圈城市基鲁纳的埃斯朗太空港发射卫星是可能的，但瑞典军队也想探索其他选择，以防发生战争。

However, it is obvious that JAS-39, as a light fighter equipped with only a single medium-thrust engine, has an empty weight of only 6.8 to 8 tons. Whether it is the load weight limit brought by the take-off weight or the load size limit brought by the ground clearance of the centerline of the belly, the air-based launch rocket that can be carried is destined to be very "pocket" - the satellite that can be carried is very small, and the orbital altitude will not be too large.

不过显而易见，JAS-39作为一种仅安装单台中等推力发动机的轻型战斗机，自身空重仅为6.8吨至8吨。 无论是起飞重量带来的载荷重量限制，还是机腹中线离地间隙带来的载荷尺寸限制，都注定能携带的空基发射火箭非常「袖珍」——能携带的卫星非常小，轨道高度也不会太大。

Carlson said that the KTH Royal Institute of Technology in Stockholm, Sweden, has conducted a preliminary study on the feasibility of the project and believes that the air-launched rocket carried by the JAS-39 can launch a 2-kilogram satellite. The next step will be to examine the impact of the ground clearance of the aircraft's belly on the safety of take-off and landing, and focus on how such rockets can be safely carried and launched by the JAS-39.

卡尔森表示，瑞典斯德哥尔摩的KTH皇家理工学院已经对该项目的可行性进行了初步研究，认为JAS-39携带的空射火箭能够发射2千克重的卫星。 下一步工作将考察该机机腹离地间隙对起降安全性的影响，并重点研究此类火箭如何能够被JAS-39安全地携带和发射。

Considering that a 2-kilogram satellite cannot carry various sensor communication payloads with complex functions and high performance indicators, the satellite capability ceiling brought by the JAS-39's launch capability is actually very low. In addition, since Sweden does not rely solely on its own military strength to face potential military threats independently (it officially joined NATO in March this year), the Swedish Air Force and Saab have drawn a clear boundary for the "Stella" project: they will not pay the huge economic cost of changing the JAS-39 fuselage design in order to cater to the function of launching satellites.

考虑到2千克重量的卫星，难以搭载功能复杂、性能指标较高的各类传感通信载荷，JAS-39的发射能力所带来的卫星能力上限其实很低。 此外，由于瑞典并不仅仅凭借自身军事力量独立面对潜在的军事威胁（已在今年3月正式加入北约），因此，瑞典空军和萨博公司已经为「斯特拉」项目划下了一条明确的边界：不会为了迎合发射卫星这一功能，付出改动JAS-39机身设计的巨大经济成本。

This decision is also in line with Sweden's usual decision-making style: it has very strict control over military spending - the JAS-39 is one level smaller in weight and size than the earlier JA-37, and the core purpose is to reduce costs.

这个决策也符合瑞典一贯的决策风格：其对军事领域的开支控制非常严格——JAS-39在重量和尺寸上都比更早的JA-37要小一个级别，核心目的就是降低成本。

Compared with Sweden, Italy is also considering developing the same capabilities. According to Aviation Week, in September 2019, the Italian Air Force and industry worked with academia to establish a frxwork agreement to explore the feasibility of launching small satellites from Italian fighter jets: Compared with the Gripen, Italy's EF-2000 European fighter is a more ideal air launch platform and has more potential in practicality than Sweden.

与瑞典相比，意大利也在考虑发展相同的能力。 根据《航空周刊》报导，2019年9月，意大利空军和工业界与学术界合作建立了一项框架协议，探索从意大利战斗机上发射小型卫星的可行性：相比鹰狮，意大利拥有的EF-2000欧洲战斗机是更理想的空中发射平台，在实用性上比瑞典更有潜力。

So far, there are very few air-based launch vehicles launched from aircraft, and all of them are based on transport aircraft. Because, in order to ensure the functions and performance indicators of satellites, the weight and size of air-based launch vehicles cannot be made very small, and usually far exceed the specifications of mainstream auxiliary fuel tanks and air-to-ground weapons of tactical aircraft.

截至目前，从飞机上发射的空基运载火箭型号很少，而且均以运输机为平台。 因为，为了保证卫星的功能和性能指标，空基运载火箭的重量和尺寸不能做得很小，通常都大大超过战术飞机主流的副油箱和空对地武器的规格级别。

For example, the Pegasus-XL air-based launch vehicle, which has already been put into practical use, can send a 443-kilogram satellite into low-Earth orbit, but it weighs 23.13 tons, is 17 meters long, and has a diameter of 1.27 meters. It also has a pair of delta wings with a wingspan of 6.7 meters, which cannot be carried by a fighter jet anyway.

比如已经实用化的「飞马座」-XL（Pegasus-XL）空基运载火箭，能将443千克的卫星送入近地轨道，但其全重达23.13吨，长17米，直径1.27米，而且它带有一对翼展达到6.7米的三角翼，这是战斗机无论如何都挂载不下的。

Later, Virgin Orbit's LauncherOne rocket was even heavier and larger than Pegasus XL.

后来维珍轨道公司的发射器一号火箭，重量和体积比「飞马座」-XL还要更大。

According to the classification of wet mass (including fuel), fighter jets can only launch nanosatellites (1-10 kg) and microsatellites (10-100 kg), and cannot even launch small satellites (100-500 kg). The actual value of fighter jets' responsive satellite launch ultimately depends on one point: what role can a nanosatellite weighing a few kilograms or at most a dozen kilograms play after being launched into low-Earth orbit?

按照湿质量（包括燃料）级别进行分类，战斗机能够发射的只有纳米卫星（1—10千克）和微型卫星（10—100千克），连小型卫星（100—500千克）都发射不了。 而战斗机响应式发射卫星的实际价值，最终取决于一点：数千克、最多十多千克的微纳卫星，发射到近地轨道以后，能起到什么样的作用？

The main military use of micro-nano satellites is to achieve various tasks such as observation, communication, remote sensing, reconnaissance, communication relay, and navigation through the mutual coordination of multiple satellites. This coordination can be in the form of a simple constellation combination. There is no fixed distribution configuration requirement between satellites. The ground coverage characteristics are maintained through single-satellite orbit control. There is no need to maintain closed-loop control between satellites, nor is there a need for information exchange and services between satellites. At the same time, a more complex and advanced satellite networking form can also be adopted to decompose the functions of a larger single traditional satellite into multiple different satellites, which coordinate with each other through wireless lixs.

微纳卫星的最主要军事用途是通过多颗卫星的相互协同，实现观测、通信、遥感、侦察、通信中继、导航等各种任务。 这种协同可以是简单的星座组合形式，卫星之间没有固定的分布构型要求，通过单星轨道控制来保持对地覆盖特性，不需要在星间保持闭路控制，也不需要星间实现信息交换和服务。 同时，也可以采用更复杂高级的卫星组网形式，把更大级别的单个传统卫星的功能分解到不同的多个卫星上，彼此之间通过无线链路进行协同。

Due to the low cost of micro-nano satellites, in theory, they can be replaced and upxed at any time, launched quickly, and form a quantitative advantage. Due to the miniaturization of high-performance devices brought about by the rapid progress of electronic technology, new micro-nano satellites can now perform tasks that previously required a larger satellite. For example, under the same mission cost limit, a 6U specification (approximately 30x20X10 cm) and 35 kg earth imaging satellite constellation under the CubeSat standard can replace the original set of 5-star fast-eye earth imaging satellites weighing 156 kg, and the revisit time interval is greatly shortened from once every 24 hours to once every 3.5 hours.

由于微纳卫星本身较低的成本，理论上它能随时替换更新、并且快速发射，并形成数量上的优势。 由于电子技术飞速进步带来的高性能器件小型化，现在的新型微纳卫星可以执行以往需要大一个级别卫星才能实现的任务。 比如在相同的任务成本限制下，使用立方星（CubeSat）标准下6U规格（大致尺寸30x20X10厘米）、35千克的地球图像卫星星座，可以替代原来一组5星重156千克的快眼地球成像卫星，而且重访时间间隔大幅度缩短，从24小时一次降低到3.5小时一次。

From the current situation, Sweden's main demand for fighter-launched nanosatellites is to carry out reconnaissance missions such as image taking of designated areas and provide real-time or semi-real-time image data to ground units, especially combat-ready forces.

从目前的情况来看，瑞典对战斗机空射纳米卫星的主要需求是对指定区域进行图像拍摄等侦察任务，并向地面单位——特别是战备部队提供实时或半实时的图像数据。

Sweden has relatively rich engineering experience in the research and development of micro-nano satellites. For example, the Swedish Aerospace Corporation developed a variety of micro-nano satellites such as Astrid-1 and Astrid-2 for the Swedish National Space Agency in the early years.

在微纳卫星的研发上，瑞典有比较丰富的工程经验，比如瑞典航天公司早年就曾经为瑞典国家空间局研发了Astrid-1和Astrid-2等多种微纳卫星。

It is worth mentioning that Astrid-1 and Astrid-2 were previously launched by Russia's Cosmos-3M light launch vehicle from the Plesetsk Cosmodrome in Russia. The new nanosatellite that may be launched by JAS-39 in Sweden itself has Russia as its biggest imaginary enemy... In less than 20 years, the geopolitical landscape of Europe has undergone tremendous changes, which is impressive.

值得一提的是，Astrid-1和Astrid-2此前都是由俄罗斯的Cosmos-3M轻型运载火箭，在俄罗斯境内的普列谢茨克航天发射场发射的。 而可能由JAS-39在瑞典本国境内发射的新型纳米卫星，最大的假想敌恰恰就是俄罗斯...... 不到20年的时间，欧洲地缘政治格局就出现了巨大的变化，令人感慨。