استفاده از رانش‌زاهای الکتریکی در ماهواره‌ها نخستین بار توسط شوروی سابق انجام گرفت. اولین رانش‌زای مورد استفاده در یک ماموریت فضایی یک رانش‌زای الکتریکی از نوع پالس پلاسمایی بود که در سال ۱۹۶۴ بر روی ماهواره زوند-۲ با ماموریت کنترل وضعیت سه محوره به پرواز درآمد. این اولین استفاده از یک رانش‌زا در فضا بود که زمینه گسترش انواع دیگر رانش‌زاهای الکتریکی را برای استفاده در ماموریت‌های فضایی پس از آن فراهم کرد.
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Secure video calling is in high demand. As an alternative to Zoom, many people are using end-to-end encrypted apps such as WhatsApp, FaceTime or Signal to speak to friends and family face-to-face since coronavirus lockdowns started to take place across the world. There’s another option—secure communications app Telegram just added video calling to its feature set, available on both iOS and Android. The new feature is also super secure—like Signal and WhatsApp and unlike Zoom (yet), video calls will be end-to-end encrypted.
With Telegram, you can send messages, photos, videos and files of any type (doc, zip, mp3, etc), as well as create groups for up to 200,000 people or channels for broadcasting to unlimited audiences. You can write to your phone contacts and find people by their usernames. As a result, Telegram is like SMS and email combined — and can take care of all your personal or business messaging needs. In addition to this, we support end-to-end encrypted voice calls.
Telegram is a messaging app with a focus on speed and security, it’s super-fast, simple and free. You can use Telegram on all your devices at the same time — your messages sync seamlessly across any number of your phones, tablets or computers.
Telegram is for everyone who wants fast and reliable messaging and calls. Business users and small teams may like the large groups, usernames, desktop apps and powerful file sharing options. You can appoint admins with advanced tools to help these communities prosper in peace. Public groups can be joined by anyone and are powerful platforms for discussions and collecting feedback.In case you're more into pictures, Telegram has animated gif search, a state of the art photo editor, and an open sticker platform (find some cool stickers here or here). What's more, there is no need to worry about disk space on your device. With Telegram's cloud support and cache management options, Telegram can take up nearly zero space on your phone.
Unlike WhatsApp, Telegram is a cloud-based messenger with seamless sync. As a result, you can access your messages from several devices at once, including tablets and computers, and share an unlimited number of photos, videos and files (doc, zip, mp3, etc.) of up to 2 GB each. And if you don't want to store all that data on your device, you can always keep it in the cloud.Thanks to our multi-data center infrastructure and encryption, Telegram is faster and way more secure. On top of that, Telegram is free and will stay free — no ads, no subscription fees, forever.
Yes! Voice calls are currently available to users around the world.
Many modern travelers appear to struggle with managing various aspects of their finances simultaneously while abroad, such as banking, budgeting, investing, trading, and saving. It is important to have apps installed on the device that will help you carry out these necessary tasks.
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